The present invention relates to a window, in particular for mounting in an inclined roof surface, comprising a frame structure and a sash structure with an insulating pane and is openable relative to the frame structure. The frame and the sash structures comprise profile members, which at least in respect of bottom and side members of the structures, are designed as solid profiles of a thermally well insulating material. A heating means is provided at least in the areas around each of the corners between the sash bottom member and the adjacent side members for preventing condensation on the adjacent corner areas of the insulating pane.
Roof windows having frame and sash structures of solid wood profiles are known, for example, from EP-A-0 251 804 and DE-A-37 05 777.
Many windows having insulating panes, in particular roof windows for mounting in inclined roof surfaces, suffer from the problem that during the cold part of the year, condensation frequently occurs on the interior side of the insulating pane, most often in the corner areas of the pane and with a distinct concentration in corner areas at the corners between the bottom member of the sash structure and the adjacent side members.
To obviate this problem it is known from GB-A-2,094,382 and DE-A-38 02 077 to place an active heat source in the form of a heater cable or strip at the corner areas in question.
In respect to windows with frame and sash structures made from hollow profiles, it is likewise known from DE-A-195 17 212 to provide a heating means in such corner areas in the form of a heat bridge arranged in the hollow space of the sash member profiles on the interior side of a profile wall facing the light admitting area.
In the light of this prior art, the object of the invention is to effectively prevent condensation in windows of the above-mentioned type having frame and sash structure made of solid profiles.
To meet this object a window according to the invention is characterized in that the heating means is established as a passive heat bridge of a well heat-conducting material integrated in a cover member arranged on the interior side facing the insulating pane of each of the parts of the bottom and side members of the sash structure bordering the corner area in question for providing a good heat-transmission from the interior side of the sash structure to said corner areas of the insulating pane.
By establishing such a heat bridge, which is possible with comparatively simple means, it is possible to eliminate or at least strongly reduce the tendency of condensation in those areas.
In a preferred embodiment in which said heat bridge is established in connection with or through the bottom and side members of the frame structure, measurements have thus confirmed that at an outdoor temperature of 0xc2x0 and a room temperature of 20xc2x0, it is possible to raise the temperature at the interior side of the insulating pane in said areas from approx. 10xc2x0 to approx. 16xc2x0, whereby the risk of condensation at normal degrees of humidity of the atmosphere is eliminated or considerably reduced.